1. Field of the Invention
The present invention relates to a microscope system which has an optical element switch unit and capability of capturing an observation image.
2. Description of the Related Art
An optical element switch unit provided for a microscope has a mechanical engagement system between the movable portion and the fixed portion of the unit so that the optical element can be set in accordance with the optical axis. In the engagement system, each time the central axis on the location of the optical element provided for the unit reaches the position of the observation optical axis of the optical device of the microscope, the turret movable portion and the fixed portion are mechanically engaged, thereby holding the positioning.
However, there can be a displacement of an optical axis generated from the mechanical positioning of an optical element switch unit relative to a microscopic vision image. In addition, although the mechanical positioning of the optical element switch unit is correct, there can be a displacement of an optical axis by the expansion and the contraction under the conditions of the environment such as the humidity, the temperature, etc.
Furthermore, in the optical elements, it is hard to correctly form a parallel plane with a parallel planar optical element. With an object lens, it is hard to set the central point of the lenses forming the object lens. Therefore, there can be a displacement of an optical axis depending on the processing precision.
According to Japanese Patent Application Laid-open No. Hei 6-313850, the amount of displacement of a microscopic vision image by the switch of an object lens and an optical element of the microscope is stored in advance, and the stage of a sample is moved by the amount of displacement, thereby removing the displacement of the microscopic vision image. In Japanese Patent Application Laid-open No. Hei 6-75172, a capture unit captures a microscopic vision image for each of a plurality of different object lenses, and the amount of displacement of a captured image of each object lens is measured and stored using the value of a pixel pitch. Then, using the value of pixel pitch stored when observation is made, the stage of the microscope is traveled and the displacement of a microscopic vision image is removed.
In Japanese Patent Application Laid-open No. Hei 6-313850 and Japanese Patent Application Laid-open No. Hei 6-75172, the problem of the displacement of a microscopic vision image by the switch of an optical element is solved by the movement of the stage by the amount of displacement.
However, when an object to be observed in a liquid is observed, the liquid waves when the stage on which the object to be observed is placed moves. Therefore, there is a high possibility that the object to be observed can move, and the observation is difficult. When the amount of displacement is very small, there is a possibility that the amount of displacement is not correct.